<script setup>
// 图片列表
import { ref, watch } from "vue";
import { useMouseInElement } from "@vueuse/core";

defineProps({
  imageList: {
    type: Array,
  }
})

const activeIndex = ref(0)

const target = ref()
const { elementX, elementY, isOutside } = useMouseInElement(target)
const px = ref(0)
const py = ref(0)

watch([elementX, elementY, isOutside], () => {
  // console.log(elementX.value, elementY.value, isOutside.value)
  if ( 100 <= elementX.value <= 300) px.value = elementX.value - 100
  if ( 100 <= elementY.value <= 300) py.value = elementY.value - 100

  if ( elementX.value <= 100 ) px.value = 0
  if ( elementX.value >= 300 ) px.value = 200

  if ( elementY.value <= 100 ) py.value = 0
  if ( elementY.value >= 300 ) py.value = 200

})

</script>


<template>
  <div class="goods-image">
    <!-- 左侧大图-->
    <div class="middle">
      <img :src="imageList[activeIndex]" alt="" ref="target"/>
      <!-- 蒙层小滑块 -->
      <div class="layer"
           v-show="!isOutside"
           :style="{ left: `${px}px`, top: `${py}px` }"></div>
    </div>
    <!-- 小图列表 -->
    <ul class="small">
      <li
        v-for="(img, i) in imageList"
        :key="i"
        :class="{active: activeIndex === i}"
        @click="activeIndex = i"
      >
        <img :src="img" alt="" />
      </li>
    </ul>
    <!-- 放大镜大图 -->
    <div class="large" :style="[
      {
        backgroundImage: `url(${imageList[activeIndex]})`,
        backgroundPositionX: `${-2*px}px`,
        backgroundPositionY: `${-2*py}px`,
      },
    ]" v-show="!isOutside"></div>
  </div>
</template>

<style scoped lang="scss">
.goods-image {
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;

  .middle {
    width: 400px;
    height: 400px;
    background: #f5f5f5;
  }

  .large {
    position: absolute;
    top: 0;
    left: 412px;
    width: 400px;
    height: 400px;
    z-index: 500;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    background-repeat: no-repeat;
    // 背景图:盒子的大小 = 2:1  将来控制背景图的移动来实现放大的效果查看 background-position
    background-size: 800px 800px;
    background-color: #f8f8f8;
  }

  .layer {
    width: 200px;
    height: 200px;
    background: rgba(0, 0, 0, 0.2);
    // 绝对定位 然后跟随咱们鼠标控制left和top属性就可以让滑块移动起来
    left: 0;
    top: 0;
    position: absolute;
  }

  .small {
    width: 80px;

    li {
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;

      &:hover,
      &.active {
        border: 2px solid $xtxColor;
      }
    }
  }
}
</style>
